Many orthopedic devices include hinges that support joints, and control and limit joint movements. These joints include the knee, elbow, shoulder, hip, ankle and wrist joints.
The knee joint comprises two joints, lateral and medial, between the femur and tibia, and one arthrodial joint between the patella and femur. The primary movements of the knee comprise flexion (i.e., rearward rotational movement of the tibia relative the femur), and extension (i.e., forward rotational movement of the tibia relative the femur).
The flexion and extension movements of the knee joint are not pivotal movements about a fixed axis. During flexion, the axis around which movement takes place shifts backward, and during extension it shifts forward. This differs from a more typical hinge joint, such as an elbow, where the axis of rotation does not shift. As full extension is reached, the tibia is rotated inward or rearward, and the joint is disposed in a “locked” position with the ligaments taut. This gives the joint greater stability in the extended position. As flexion is initiated, the tibia initially lowers or moves downwardly with small external rotation of the tibia unlocking the joint and subsequently the tibia rotates or rolls about the joint to full flexion. The initial unlocking of the knee joint during flexion precedes actual full rotation of the knee.
Because of the complexity associated with knee movement a knee brace hinge must be able to simulate the movements of the knee. Incorporating such hinge is crucial, as the knee brace must optimally support the knee joint of its user.
In postsurgical applications, the requirement for such simulation of the knee joint is essential to rehabilitate and prevent re-injury of an injured knee joint. The hinge should also control the range of the knee joint flexion and extension so the knee is not reinjured due to hyperextension or flexion. As the optimal range of knee joint motion may vary between users and change during the progress of rehabilitation, the hinge used with such surgical applications should further be adjustable to correspond to the motion range of the user's leg.
In recognizing the need for an effective postsurgical knee brace, various types of hinges have been incorporated into known knee braces for postsurgical applications. However, most conventional hinges typically fail to provide the precise simulation of knee joint movement or control the range of knee joint motion. Such deficiencies inevitably decrease the user's knee joint being properly rehabilitated after surgery. Further, some known hinges fail to possess sufficient adjustability to provide, quickly and easily, the optimal set range of knee motion depending upon the current user's needs and rehabilitation progress.
In view of the shortcomings of conventional knee brace hinges. There exists a substantial need in the art for a hinge that can closely simulate the motion of the knee joint while regulating the range of its flexion and extension. It is desirable to provide a hinge that can be easily and quickly adjusted to provide a variable, optimal range of knee joint flexion and extension for the need of its user.
Many contemporary knee braces fail to provide the precise simulation of knee joint movement or have comprised relatively heavy, bulky apparatus, detracting from the user's athletic endeavor. Further, known designs fail to possess sufficient structural integrity to prevent re-injury of the knee joint as may be occasioned by impact to the knee joint during physical sport endeavors.
The features of the present invention are provided in recognition of the need for orthopedic braces and hinge streamlined, low profile, and easy to adjust while supporting joints and controlling and limiting joint movement. This recognition is realized with the invention described.